Battery Problem with Tadao?

i was just wondering if this is normal
Played with my dm4 sunday at a tourney
first game dm4 didn't work, blue light turned on, but it wouldn't fire
gun was gased up and ready to go
blue light remained on but nothing happend when i pulled the trigger, i had a few ppl look at it, no one knew at first, then someone said change the batteries
once i changed the batteries it worked great
question is: Isn't there a warning to tell low battery or anything,
just seemed weird to me, blue light was on, wasn't faded or flickering
i thought tadao had low battery warning?

does the same thing on my tadao chip... but it is noticable when it happens so my guess is if you dont have an lbi board then that is what trys to tell you your battery is low... lol just my guess or they could have n ot known about it and did it on accident while making the chip